.308 Seating depth

G-Lo

G-Lo

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Hello all-

I want ask to those who reload .308 for their bolt action rifles if you have gone through the process of finding the OAL of your rifle and seating the bullet with a jump off the lands and whether you have seen a noticeable improvement in your groups.

I shoot a Rem. 700 SPS 26" heavy barrel, 1:12 and I have tried with an OAL gauge to determine the OAL of the rilfe. However Remington rifles have a very long throat and if I would seat with a 0.020 off the lands the bullet barely seats on the case.

In my case am I just left developing a load and playing with the OAL as far as the bolt would close?

I am not a very experienced reloader, so I appreciate any suggestions, critique etc.

Thanks for reading.
 
I seat my bullets in my bolt gun just off the lands which is where it is most accurate. You can try another bullet that will allow you to get near the lands and still be retained by the case. What are you loading and at what distance are you shooting them?
 
highscore said:
I seat my bullets in my bolt gun just off the lands which is where it is most accurate. You can try another bullet that will allow you to get near the lands and still be retained by the case. What are you loading and at what distance are you shooting them?
Click to expand...

Right now I have tried only 168gr Sierra, Hornady A-Max and Nosler CC.
I do have some 155gr on the way and some 175. Right now only shooting at 200yds, but would like to qualify for 600yds.

I get really long measurements at the lands, so I'm not sure a different bullet would allow me to seat it so that the case would retain. Clearly I'm hoping I'm not wrong on my measurements, but I have repeated several times and the numbers don't vary that much.
 
For a rough try, I'll partially resize the necks of some brass, and seat a bullet ridiculously long, then chamber 3 of those rounds. Usually they all come back with the same number, occasionally a bullet will get stuck in the lands and pull out a bit from the case mouth. I start with this measurement and then adjust seating depth until it does not contact the lands, then start backing off until I find that sweet spot.

Are you using a bullet comparator to measure seating depth?

Each rifle has it's own personality. My pet rifle, a rem 700 VLS .223 absolutely loves the economical plain Jane varmint bullet Sierra 45gr flat based spitzer, #1310 over 25gr of 3031. Not a match bullet by far, and a so so powder by many, but you'd be hard pressed not to shoot under 1/2in under any circumstance.

Try different aspects in small batches only changing one thing at a time so you can identify things that work and don't work. Take detailed notes so you can single out the variables.
 
Why do remingtons have such a long throat? Is this a CYA by remington so everything out there will fit with out craming into the lands?
Do you plan on single loading more often than feeding it through the mag.
I dont have any tight chambered 30 cal rifles. I run into the same issue. Bullet is balancing out of the neck of the case. 308 is one cal I do not have yet.
Been reading and it seems 1;12 is good for 168s and below. Now what do you plan on shooting more?
Is the SPS a Varmint model ?
 
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The first place to start is what will fit in the magazine. 2.800" is the accepted max. OAL. If your magazine accepts a much longer round, you might want to try a heavier bullet and follow Stape's advice. For example, you could try 175 grain bullets seated way out. Some bullets like being in the lands. Some don't.
 
Stape said:
For a rough try, I'll partially resize the necks of some brass, and seat a bullet ridiculously long, then chamber 3 of those rounds. Usually they all come back with the same number, occasionally a bullet will get stuck in the lands and pull out a bit from the case mouth. I start with this measurement and then adjust seating depth until it does not contact the lands, then start backing off until I find that sweet spot.

Are you using a bullet comparator to measure seating depth?

Each rifle has it's own personality. My pet rifle, a rem 700 VLS .223 absolutely loves the economical plain Jane varmint bullet Sierra 45gr flat based spitzer, #1310 over 25gr of 3031. Not a match bullet by far, and a so so powder by many, but you'd be hard pressed not to shoot under 1/2in under any circumstance.

Try different aspects in small batches only changing one thing at a time so you can identify things that work and don't work. Take detailed notes so you can single out the variables.
Click to expand...

Thank you Stape.

I did try that method by resizing a case just enough to hold the bullet and chamber it a few times. I was getting measurements in the 2.9600 range. Hard to believe would be sitting that long. Then I decided to use the OAL gauge but I'm having doubts I'm doing it right, however the measurements I was getting would barely allow the bullet to be seated in the case.

I do have a bullet comparator, but I'm waiting to get the insert so I'll be able to measure from the ogive.

I will repeat the first method again a few times with different bullets and see if I can get constant measurements and go from there. I just get nervous as I don't want to run into pressure problems.

And you are correct detailed notes are the key. I have loaded the Sierra 168 from min load of 42gr to 46gr with Varget. And some groups are certainly better than others.

I realize that seating depth is just one aspect of precision reloading, as brass, primers and dies also play a big part of it. I'm just tackling seating depth at the moment to see if I can find what my rifle likes.
 
mac1911 said:
Why do remingtons have such a long throat? Is this a CYA by remington so everything out there will fit with out craming into the lands?
Do you plan on single loading more often than feeding it through the mag.
I dont have any tight chambered 30 cal rifles. I run into the same issue. Bullet is balancing out of the neck of the case. 308 is one cal I do not have yet.
Been reading and it seems 1;12 is good for 168s and below. Now what do you plan on shooting more?
Is the SPS a Varmint model ?
Click to expand...

You are correct Mac. From what I have gathered, Remington purposely has their barrel with very long throat to make it virtually impossible for someone to blow the rifles or themselves up.

I don't plan to use the magazines. For my type of shooting I load one round at the time. Plus my rifle does not have a detachable magazine, but just a blind hinged magazine, which I dislike anyways.

And again correct, 1:12 barrels like the range of 155 to 168gr best, but also up to 175gr you can get good results.

I believe the SPS comes into model SPS Varmint (26") and Tactical (20"). The 26 inches has a heavy barrel. Certainly not for hunting as it's pretty heavy.
 
ztargetshooter said:
How are your groups now? If they are good, don't worry about it.
Click to expand...

My best group was 1.20 inch at 200yds (group of 3 shots), and that was with Nosler Custom comp 168gr over 44.0gr of Varget, seated at 2.8100.

I would like to get more of those on a regular basis. Naturally I need to do my part as well.
 
Powders play a huge roll in accuracy as well. In my experience, Varget has always been a good performer for every application it is indicated, but it has never been the best in regards to accuracy. I've got a few 308's but none I would consider a precision weapon. Closest I have to that in 308 is a Ruger Scout rifle, and I use Varget for it and get 2in groups at 100 but that's with those rough/ sturdy battle sights. I thought about putting glass on it to see what I can get it to do, but it's just not the rifle for it for my uses ect. I run 4064 in my M1A's with great results, and have some 748 I need to try.
 
Stape said:
Powders play a huge roll in accuracy as well. In my experience, Varget has always been a good performer for every application it is indicated, but it has never been the best in regards to accuracy. I've got a few 308's but none I would consider a precision weapon. Closest I have to that in 308 is a Ruger Scout rifle, and I use Varget for it and get 2in groups at 100 but that's with those rough/ sturdy battle sights. I thought about putting glass on it to see what I can get it to do, but it's just not the rifle for it for my uses ect. I run 4064 in my M1A's with great results, and have some 748 I need to try.
Click to expand...

Yes, that's on my list of powders to try as I have read quite a few comments out there of people preferring 4064 over varget as they get better accuracy. Might have to abandon playing with OAL until I feel I'm doing it right.
 
Stape said:
1.2in at 200 is doing really well. Personally, I'd leave it alone. Thats really good for what I'm assuming is a factory rifle.
Click to expand...
I tend to agree. The only thing i replaced is the stock. Everything else is factory. I will put a couple of thousands rounds and by then i will have more knowledge and a better idea of what i like and dont in my "ideal" rifle. And hopefully by then i will have the funds for a custom built.
 
G-Lo said:
I tend to agree. The only thing i replaced is the stock. Everything else is factory. I will put a couple of thousands rounds and by then i will have more knowledge and a better idea of what i like and dont in my "ideal" rifle. And hopefully by then i will have the funds for a custom built.
Click to expand...

If you are committed to long distance it may be worth taking the rifle to a gunsmith and have him set the barrel back a bit. A couple thousand rounds of reloads is a huge investment in time and money.

What if you realize that your rifle prefers the longest rounds you can make with the least jump. Then you will wonder what your rifle could do with less freebore. What then?
 
ztargetshooter said:
If you are committed to long distance it may be worth taking the rifle to a gunsmith and have him set the barrel back a bit. A couple thousand rounds of reloads is a huge investment in time and money.

What if you realize that your rifle prefers the longest rounds you can make with the least jump. Then you will wonder what your rifle could do with less freebore. What then?
Click to expand...
Thanks for the input. Thats a good point and good idea. I will talk to my gunsmith and see what can be done.
 
ztargetshooter said:
If you are committed to long distance it may be worth taking the rifle to a gunsmith and have him set the barrel back a bit. A couple thousand rounds of reloads is a huge investment in time and money.

What if you realize that your rifle prefers the longest rounds you can make with the least jump. Then you will wonder what your rifle could do with less freebore. What then?
Click to expand...

This sounds like a good idea but if the free bore is cut that long your not going to gain that much, for lack of a visual. would new extractor cuts need be made, barrel shoulder turned back.... buy the time your down you most likely could have purchased and installed a short chambered barrel with a short free bore/lead... This may or may not help. I have a 1903A3 that I wanted to try seating close to the lands. I did as you did. In my frustration I seated a 168gn Amax ever so slightly passed the boat tail taper. I then slowly tried to close the action. I then by a 1/4 turn on the seating die set the bullet deeper until I could close the action with just the slightest of effort.
Sadly what I found is my free bore is long so long as I dont feel safe seating my bullets with so little in the neck....
 
G-Lo said:
Thanks for the input. Thats a good point and good idea. I will talk to my gunsmith and see what can be done.
Click to expand...

No, it's not a good idea. If you couldn't get stellar accuracy with a long chamber do you think Remington would've left it that way?

You don't have to jam a bullet into (or even near) the lands in order to get outstanding accuracy. Just find the right bullet. The shape of the bullet determines how or if jump will affect the accuracy.

A secant ogive bullet will tolerate a lot of jump. A bit of freebore will also enable yo to achieve higher velocity with similar pressure. Higher velocity gives you a flatter trajectory and a shorter time in flight,both of which help accuracy.

As far as your OAL goes, you have a range available to you. The short end is what is published in the reloading manual. The long end is the shorter of these three parameters:

  1. The length where the bullet is 0.010" from the lands*
  2. Magazine length
  3. The length where a minimum of one caliber's length of the bearing surface of the bullet is seated into the case neck**
*You can go right up to the lands if you're not loading near max
** For cases where the neck is less than one caliber in length, seat the full length of the neck.


You can experiment within this range to find the sweet spot.

Read this: http://www.bergerbullets.com/getting-the-best-precision-and-accuracy-from-vld-bullets-in-your-rifle/
 
EddieCoyle said:
No, it's not a good idea. If you couldn't get stellar accuracy with a long chamber do you think Remington would've left it that way?

You don't have to jam a bullet into (or even near) the lands in order to get outstanding accuracy. Just find the right bullet. The shape of the bullet determines how or if jump will affect the accuracy.

A secant ogive bullet will tolerate a lot of jump. A bit of freebore will also enable yo to achieve higher velocity with similar pressure. Higher velocity gives you a flatter trajectory and a shorter time in flight,both of which help accuracy.

As far as your OAL goes, you have a range available to you. The short end is what is published in the reloading manual. The long end is the shorter of these three parameters:

  1. The length where the bullet is 0.010" from the lands*
  2. Magazine length
  3. The length where a minimum of one caliber's length of the bearing surface of the bullet is seated into the case neck**
*You can go right up to the lands if you're not loading near max
** For cases where the neck is less than one caliber in length, seat the full length of the neck.


You can experiment within this range to find the sweet spot.

Read this: http://www.bergerbullets.com/getting-the-best-precision-and-accuracy-from-vld-bullets-in-your-rifle/
Click to expand...
Thanks EC. Always great info. I was hoping you would chime in.

So if the distance to the lands would not allow me to seat the bullet safely in the case even backing off 0.10 i would be left with point 3 in your response. That is i would seat the bullet the lenght of the neck and then start backing off from there. Do i have that correct?
I dont use a magazine.
Also so far i have used Sierra MK in 168gr and Nosler CC and Hornady A-Max also 168gr.

I am just tryng to determine correctly the distance that just touches the lands. But.i am getting different meaurements each time i try.
 
Well now since it seems Remington leaves these barrels chamber with a long throat.
trying to seat of the lands seems futile .......
seat the bullet .308" into the case neck.......
 
You should be grateful that you are getting sub moa with a Remmington factory offering, me personally I am at least .100 of the lands it is called Jumping the lands, that is what works best for me, if you think your Rem has a lot of free bore, you have obviously never seen a Weatherby chamber, you would think something is wrong,

Dean
 
Dean Crawford said:
You should be grateful that you are getting sub moa with a Remmington factory offering, me personally I am at least .100 of the lands it is called Jumping the lands, that is what works best for me, if you think your Rem has a lot of free bore, you have obviously never seen a Weatherby chamber, you would think something is wrong,

Dean
Click to expand...
Thanks Dean. I do appreciate i am getting sub to moa with my factory Rem. I am just learning how to improve accuracy and get the most out of the rifle. I love reloading specially for rifle so this is a good excercise for me. Thanks for your comments.
 
Great info
just what I needed
thx


EddieCoyle said:
No, it's not a good idea. If you couldn't get stellar accuracy with a long chamber do you think Remington would've left it that way?

You don't have to jam a bullet into (or even near) the lands in order to get outstanding accuracy. Just find the right bullet. The shape of the bullet determines how or if jump will affect the accuracy.

A secant ogive bullet will tolerate a lot of jump. A bit of freebore will also enable yo to achieve higher velocity with similar pressure. Higher velocity gives you a flatter trajectory and a shorter time in flight,both of which help accuracy.

As far as your OAL goes, you have a range available to you. The short end is what is published in the reloading manual. The long end is the shorter of these three parameters:

  1. The length where the bullet is 0.010" from the lands*
  2. Magazine length
  3. The length where a minimum of one caliber's length of the bearing surface of the bullet is seated into the case neck**
*You can go right up to the lands if you're not loading near max
** For cases where the neck is less than one caliber in length, seat the full length of the neck.


You can experiment within this range to find the sweet spot.

Read this: http://www.bergerbullets.com/getting-the-best-precision-and-accuracy-from-vld-bullets-in-your-rifle/
Click to expand...
 

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